Quarantine Checklist for Reef Keeping

Use a bare-bottom 10 to 20 gallon tank for small fish like gobies or clownfish, and 20 to 40 gallons for tangs, wrasses, or multiple arrivals. Overcrowding in quarantine increases ammonia spikes and stress-related disease outbreaks.

Never quarantine corals and invertebrates with medicated fish because copper and many fish treatments are toxic to shrimp, snails, crabs, and corals. A separate coral QT also lets you monitor for flatworms, nudibranchs, vermetids, and nuisance algae without exposing your reef.

Use separate nets, buckets, tubing, frag racks, algae scrapers, and specimen containers for each quarantine system. Cross contamination is a common way hobbyists accidentally move Cryptocaryon, velvet, or coral pests into a display tank.

Fish often arrive stressed from shipping and do better in a stable location away from slamming doors, bright windows, and constant foot traffic. Lower stress improves feeding response and makes it easier to observe flashing, heavy breathing, or fin damage.

Prepare saltwater at 1.025 to 1.026 SG for most reef fish and corals unless a supplier specifies otherwise. Aim for 77 to 78.5 F, pH 8.0 to 8.3, and stable salinity so acclimation is gentle and not compounded by parameter swings.

Have a clear plan before livestock enters the system, such as observation only, copper protocol for ich and velvet, or tank transfer method. Changing strategy mid-process often leads to missed doses, rushed purchases, and poor disease control.

Use a heater sized for the tank and verify it with a separate thermometer rather than trusting the heater dial alone. Temperature swings of even 2 to 3 F in a small QT can suppress appetite and worsen shipping stress.

Keep extra sponge filters or ceramic media seeded in your main system sump so they are ready for quarantine when needed. This helps process ammonia immediately, which is especially important in bare-bottom fish quarantine tanks with heavy feeding.

Wrasses, firefish, dartfish, and many other marine species are strong jumpers, especially when startled in a bare quarantine environment. A secure lid prevents losses during acclimation and treatment.

PVC fittings give fish shelter without absorbing medication or trapping detritus like live rock would. Multiple hide spots reduce aggression and help shy fish settle in enough to begin feeding.

Have a Seachem Ammonia Alert badge or equivalent in the tank and confirm with liquid tests when readings are questionable. In quarantine, ammonia can rise fast, and levels above 0.2 ppm total ammonia deserve immediate attention.

Common supplies include copper test kits, praziquantel, methylene blue, fish-safe antibiotics as needed, coral dips, iodine dips, and Bayer alternative or commercial pest dip depending on your coral protocol. Buying meds after symptoms appear wastes valuable time during the highest-risk period.

Look for torn fins, cloudy eyes, excess mucus, rapid gilling, tissue recession, flatworms, egg spirals, algae, and hitchhikers before the animal enters quarantine. Early visual notes help you decide whether observation, dip, or immediate treatment is appropriate.

Many shipped fish arrive in water well below reef salinity, sometimes near 1.020 to 1.023 SG, while coral shipments may vary widely. Knowing the starting point helps you avoid osmotic shock during transfer into quarantine water.

For fish in poor shipping water, prolonged drip acclimation can increase exposure to rising ammonia after the bag is opened. A better approach is often temperature equalization followed by a measured transfer once salinity differences are understood.

Use a coral-specific dip according to label directions to knock off pests such as Acropora eating flatworms, red bugs, montipora nudibranchs, and some hitchhiking crabs. Rinse in clean saltwater before placing frags into QT to reduce carryover of dip residue and pests.

Net fish or transfer with a specimen container, and place corals after dip and rinse rather than pouring bag water into the system. This reduces the introduction of pathogens, copper residue, organics, and nuisance algae spores.

Keep fish QT lighting minimal for the first 24 hours, and acclimate corals under reduced PAR before ramping up. Sudden bright light can stress fish and shock corals that were shipped in darkness for many hours.

New quarantine systems can cycle unpredictably, especially with multiple fish or heavy feeding. If ammonia is detectable, perform a water change immediately and consider a detoxifier while maintaining oxygenation.

Small quarantine tanks evaporate quickly, and salinity creep can become significant in just a day or two. Top off with fresh RO/DI water, not saltwater, to keep SG stable within about 0.001.

Frequent small feedings help skinny or stressed fish regain weight without overwhelming biofiltration. Siphon uneaten food and feces daily so detritus does not drive ammonia or bacterial blooms.

Count for heavy breathing, flashing, head twitching, clamped fins, white dots, dusting, or refusal to eat. Fast detection is essential because marine velvet can progress much faster than common ich and may require immediate action.

Blue-only viewing can hide tissue loss, eggs, bite marks, and algae patches on frag plugs. Check corals under white light several times per week so pests and bacterial issues are caught before transfer to the display.

For stony corals, target roughly 7.5 to 9.0 dKH alkalinity, 400 to 450 ppm calcium, and 1250 to 1400 ppm magnesium. Even in a small coral QT, swings in dKH are a common cause of poor polyp extension and tissue recession.

If using copper for fish, keep it at the manufacturer's therapeutic range, commonly around 2.0 to 2.5 ppm for chelated copper products, and confirm with a compatible copper test. Under-dosing fails to control disease, while overdosing can suppress appetite and harm sensitive species.

Many treatments reduce oxygen availability or increase fish stress, so an air stone or vigorous sponge filter is important. This matters even more at warmer temperatures or with fish already breathing heavily.

A practical fish quarantine period is often 30 days minimum, with many hobbyists extending to 45 days when disease risk is high. Corals are often held 30 to 76 days depending on the pest prevention strategy and the goal of avoiding fish-borne parasite transfer on wet surfaces.

Some coral pests are not fully eliminated by a single dip because eggs can survive. Repeat inspections and follow-up dips at planned intervals, especially for Acropora, montipora, zoanthids, and euphyllia from mixed systems.

These materials can absorb copper and make dosage unstable, leading to inaccurate therapeutic levels. Bare-bottom tanks with inert decor are easier to clean and safer for controlled treatment.

A written log prevents skipped doses and helps you judge whether a fish is improving or declining over several days. It is also useful when comparing fish appetite, respiration, and ammonia levels throughout quarantine.

Before moving to the display, fish should show normal respiration, strong feeding response, intact fins, and no visible spots or flashing. A fish that is still thin or inconsistent at feeding is better left in quarantine longer.

Scrape or replace frag plugs when practical, especially if algae, vermetids, hydroids, or suspicious egg clusters are present. Many pests hide on plug undersides and bases rather than on visible coral tissue.

Even after weeks in QT, differences in temperature, salinity, and alkalinity can still cause stress. Check SG, temperature, and for corals, compare dKH and light intensity before transfer to avoid preventable shock.

After a quarantine cycle, clean tanks, heaters, PVC, and tools with an appropriate disinfecting method and rinse thoroughly. Drying equipment fully adds another layer of protection against many pathogens and pests.

Media used in copper or other fish medications should not be reused casually in reef systems or invert setups. Keep fresh seeded sponges or ceramic media ready so the next quarantine can be started without delay.